1. Field of the Invention
The present invention relates to an acetabular cup prosthesis, and, more particularly, to a metal-backed, polymeric acetabular cup prosthesis.
2. Description of the Related Art
It is known to provide an acetabular cup prosthesis having a plastic cup with a metal backing. The metal backing may be in the form of a woven metal grid which is sized to allow bone tissue to grow therein.
With known acetabular cup prostheses, the outside diameter of the cup may vary depending on the size of the pelvic bone of the patient into which the acetabular cup prosthesis is to be implanted. Changing the outside diameter of the acetabular cup in turn changes the radial stiffness of the cup. A radial stiffness which is not stiff enough may hasten deterioration of the polymeric cup and cause pinching of the femoral head, while a radial stiffness which is too stiff may not allow proper loading and stimulation of the bone tissue to encourage ingrowth of the bone into the metal backing.
What is needed in the art is an acetabular cup which may be constructed to substantially conform to a normalized radial stiffness, regardless of the outside diameter of the cup.
What is further needed in the art is an acetabular cup which ensures an adequate attachment between the polymeric cup and metal backing.